Highly Efficient Method for the Synthesis of Carboxamides from Carboxylic Acids and Amines Using Benzenesulfonic Anhydride (BSA)

Abstract A highly efficient method by using benzenesulfonic anhydride (BSA) in the presence of 4-(dimethylamino)pyridine (DMAP) to synthesize carboxamides from various carboxylic acids and amines including sterically hindered ones is established. This reaction proceeds smoothly to provide the desired product in high yield.